From the related art, a laser scanning type image display device displaying an image by scanning laser light on a screen is known. In a laser scanning type method, color reproducibility is high, and black floating does not occurs, compared to a method in which image light formed on an image display element such as a liquid crystal panel is projected by using a light emitting diode as a light source. However, there is a problem in that the laser light has coherence, and thus, a random interference pattern referred to as a speckle is generated.
For example, in Patent Document 1, as a technology of preventing the speckle from being generated, a technology is disclosed in which a screen is configured of at least two diffusion members, and at least one diffusion member is oscillated, and thus, an image is viewed without being affected by speckle noise. In addition, it is known that it is possible to reduce the speckle noise by increasing a diffusion angle of the diffusion member used as the screen, compared to a case where the diffusion angle is small (for example, refer to Patent Document 2).